attritionat·tri·tion /əˈtrɪʃən/ noun [uncountableU]1HUMAN RESOURCES the process of reducing the number of employees by not replacing those who leave for normal reasons, such as changing jobs, RETIREMENT (=leaving a job when you reach a certain age) etcThe bank plans to reduce its staff by as much as 5% this year by natural attrition.
2MARKETING when customers are lost, for example because they start buying a competitor’s productThe success of this credit card has contributed to the attrition of card holders from other issuers.